Brake release mechanisms are provided on vehicles having spring applied, pressure released brakes in order to release the brakes for towing in the event that the vehicle becomes disabled. Many of the well known brake release mechanisms are mounted directly on the vehicle, thus requiring various components for each vehicle. These components; such as, control valves, check valves, manual shutoff valves, auxiliary hand pumps and associated lines add complexity and extra cost to each vehicle. Other brake release mechanisms that are not mounted directly on the vehicle are normally coupled to the existing lines and uses the vehicle brake control valve to release the brakes. These mechanisms experience varying degrees of leakage due to the pressurized fluid from the auxiliary pump being directed through the brake control valve. Consequently, a larger source of pressurized auxiliary fluid is needed to maintain the brakes in the released condition while towing the vehicle.
The present invention is directed to overcoming one or more of the problems as set forth above.